title: Surviving in a marine desert: the sponge loop retains resources within coral reefs.
abstract: Ever since Darwin's early descriptions of coral reefs, scientists have debated how one of the world's most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is transferred to higher trophic levels. Here we show that sponges make DOM available to fauna by rapidly expelling filter cells as detritus that is subsequently consumed by reef fauna. This "sponge loop" was confirmed in aquarium and in situ food web experiments, using (13)C- and (15)N-enriched DOM. The DOM-sponge-fauna pathway explains why biological hot spots such as coral reefs persist in oligotrophic seas--the reef's paradox--and has implications for reef ecosystem functioning and conservation strategies.
authors.affiliation: Department of Aquatic Ecology and Ecotoxicology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Post Office Box 94248, 1090 GE Amsterdam, Netherlands. j.m.degoeij@uva.nl
authors.forename: Jasper M
authors.initials: JM
authors.lastname: de Goeij
authors.forename: Dick
authors.initials: D
authors.lastname: van Oevelen
authors.forename: Mark J A
authors.initials: MJ
authors.lastname: Vermeij
authors.forename: Ronald
authors.initials: R
authors.lastname: Osinga
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Middelburg
authors.forename: Anton F P M
authors.initials: AF
authors.lastname: de Goeij
authors.forename: Wim
authors.initials: W
authors.lastname: Admiraal
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000378:metabolism*; D057894:Coral Reefs